2. Field of Invention
This patent relates to the use of exercise machines, specifically to an exercising regime for a person while in bed. The invention can also be used as a physical therapy and rehabilitation programs to restore and/or maintain functional mobility in bedridden patients.
3. Information Disclosure Statement
For the geriatric population especially, losing the muscle strength that is required to get up out of bed and walk with confidence can mean the difference between independent living and permanent dependence on others. Decreased functional mobility has a drastic effect on quality of life and has been found to significantly predict mortality. (Laukkanen, P., Heikkinen, E., Kauppinen, M., Muscle Strength And Mobility As Predictors Of Survival In 75-84 Year Old People. Age and Aging, 24:468-473, 1995.) Addressing the loss of functional mobility in the elderly through appropriate exercise programs will reduce long term health care costs and improve the quality of life of the elderly.
One major cause of decreased functional mobility especially in the elderly is disuse atrophy of the thigh and leg muscles. Rapid disuse atrophy of the thigh and leg muscles of the elderly occurs during 5-10 days of bedrest in the bospital. In 1979, the elderly experienced 14.8 hospitalizations per 100 persons per year compared to 9.8 in the general public (Institute of Medicine, Disability in America: Toward a National Agenda for Prevention. Washington, DC., National Academy Press, 1991). Hospitalized patients, institutionalized residents, and those returning home after hospitalization are all at risk of muscular atrophy and subsequent mobility impairment due to extended bedrest. In fact, the return to premorbid function after a period of bedrest can take longer than the recovery from the original illness.
In today's hospital, nursing home and home-care settings, bed-ridden patients are dependent on physical therapists to provide the necessary exercise. The exercise provided manually by a physical therapist often does not adequately exercise tee thigh and leg muscles. Adequate exercise of the thigh and leg muscles can be achieved by following these seven basic principles of resistance training (Flech, S. J. and Kraemer, W. J., Designing Resistance Training Programs, 2nd ed. Champaign, Ill., Human Kinetics, 1997).
1. Overloading of the muscles must occur through voluntary muscular actions. For the thigh and leg muscles, this requires a level of force up to and in excess of the patient's body weight. Physical therapists cannot achieve or sustain the production of body-weight-level force at bedside.
2. Intensity during exercise is required to increase the power output of the muscles and not just their ability to overcome maximal resistances. Intensity is achieved by moving against resistance with rapid speed. Physical therapists cannot sustain manually the necessary resistance and rapid motion.
3. Training volume is a measure of the total work (Joules) performed over a time period. Training volume is important to the development lean body mass and to decreasing body fat. Physical therapists cannot measure the training volume of the exercise they provide at bedside.
4. Periodization refers to incorporating variation in training volume and intensity. Periodization is essential for optimal gains in strength. Without the ability to measure training volume and intensity, physical therapists cannot take fill advantage of the benefits of periodization.
5. Progressive overloading of the muscles is required to produce gains in strength and power. This is accomplished by progressively increasing the force level, the number of exercise sets and the training volume. Physical therapists can only provide progressive overloading within their own strength and endurance capabilities.
6. Rest periods between sets of an exercise, between exercises and between training sessions are essential to the success of a program. Rest periods should be determined in accordance with the goals of the timing program and should not be restricted by the availability of a physical therapist.
7. Specificity means that each muscle group requiring strength must be trained in a fashion similar to that required during use. The actions of walking, ascending and descending stairs, sitting down and standing up require multiple joint movements with concentric and eccentric power production in reciprocal and bilateral leg extension with body-weight-level forces. As explained above, physical therapists cannot manually orchestrate exercises that simulate these actions at bedside.
The elderly are often caught in a vicious cycle. They may be confined to bed as a result of a fall, a physical illness, depression or a lifestyle change. Without adequate exercise, their leg muscles atrophy in a week or two and they lose strength. They continue to weaken from lack of exercise. Eventually, they often lose the strength required to get up and walk. The end result is a complete bedridden state and total dependence on others. Herein, "bedridden" means any individual who cannot rise from a supine or seated position without assistance and who cannot walk without assistance and who has remained in this condition for more than two consecutive weeks. This depressing situation will only worsen as the healthcare system experiences further cost pressures, and as our population ages.
Physical therapy gyms have successfully integrated some technologies which simulate walking and weight-bearing motions (e.g. the horizontal "leg press," the recumbent cycle ergometer, the Cybexe.RTM., (registered trademark of CyBex International, Inc.) and the NuStep.RTM. (registered trademark of Life Plus, Inc.). Similarly, physical therapy gyms may employ a combination of supine exercisers such as the Total Gym.RTM., (registered trademark of Engineering Fitness International Corp.) Shuttle.RTM. (registered trademark of Contemporary Design Co.). Unfortunately, all of the devices that are capable of providing adequate exercise require that patients transfer from the bed to another location. Such transfer is labor intensive for a hospital or nursing home and is often dangerous and traumatic for a deconditioned patient. For these reasons, it is best for bedridden patients to exercise in bed.
In order to provide adequate exercise as defined by the above described seven principles, in the context of a bed, the following three criteria must be met:
I. A means of providing forces up to body weight and a bit beyond PA1 II. A means of joining any bed and the exercise machine into a single exercise unit that is capable of safely supporting said body-weight-level forces and the reaction forces from the patient. PA1 III. A means of providing said forces in a manner that simulates weight bearing and functional activity. Functional activities involve multiple joint motions that are both concentric wherein the muscle contracts under tension and eccentric wherein the muscle elongates under tension.
A review of patents on In-Bed Exerciser equipment illustrates how the state of the art fails to meet these three criteria for an In-Bed Exerciser capable of providing adequate exercise.
U.S. Pat. No. 5,820,519 describes an exercising machine designed for use in bed. This exercise machine is comprised of a torque drum mounted for rotation against a variable resistance torque drum mounted on the headboard of the bed. A cable extends from each torque drum to handles and stirrups tat attach to the hands and feet of the patient in bed. This device allows the patient to do to exercise the upper and lower extremity in a supine position. However, there is no provision in this device that allows for the application of body-weight-level forces. This is evident because all of the forces of exercise are transmitted to the headboard of the bed in the horizontal plane. The headboard of a standard bed is not designed to supporting the body-weight-level forces in the horizontal plane. The resulting torque due to the application of body-weight-level forces into the headboard could result in the catastrophic failure of the bed frame and potential serious injury to the patient. This invention is the same as lifting weights providing concentric and eccentric modes only to the biceps and triceps.
U.S. Pat. No. 5,207,628 is a device that provides for doing various exercises including sit-up and pull-up motions. There is also a provision for the attachment of rubber bands enabling a variety of exercises. Although it is conceivable that body-weight-level forces could be applied with the use of rubber bands, there are three distinct disadvantages. 1) The force provided by a rubber band is dependent on its extension length resulting in an exercise motion that does not resemble the essentially constant force of walling, a knee bend or other functional activities. 2) It is necessary to interchange the rubber band to change the force level which is a cumbersome process and not easily adaptable to fine adjustment of the force level. 3) The use of body-weight-level force rubber bands is potentially dangerous to the patient because of the unrestrained speed and path of motion.
U.S. Pat. No. 5,312,315 is for a pneumatic variable resistance rehabilitation therapy apparatus. This device provides exercise resembling functional activity for injured, weakened and post-operative ligaments and muscles of lower extremity. This device is not designed for use by bedridden patients without transferring the patient from the bed to the exercising machine. It is not obvious how this invention can be adapted for use in bed because of the integral design feature that the bed must shuttle back and forth.
U.S. Pat. No. 5,005,829 is for an exercising device used by patients confined to bed. This device allows the patient to exercise all four limbs. Force is provided by fluid resistance and there is no energy source. With the absence of an energy source, this device is unable to simulate functional activity. The force of exercise is furthermore transferred to the foot board of the bed which is not usually capable of withstanding body-weight-level forces in the horizontal plane.
U.S. Pat. No. 4,979,737 is for an exercising apparatus for the lower extremity for use in bed, on a training table or on the floor with legs extended horizontally. Force is provided with a braking resistance device and not with an energy source.
U.S. Pat. No. 4,976,426 is for an exercising device used by bedridden patients and those in different stages of rehabilitation. This device comprises that least one pair of crank arms and a hydraulic motor to rotate the crank arms with hydraulic power. This device includes a support table and therefore it is necessary to transfer the patient from the bed to this exercise apparatus.
U.S. Pat. No. 4,925,184 comprises a bicycle-like exercising device enabling a patient to exercise while in bed. This device contains no energy source. This device also is not designed to supply body weight level forces to the subject. This device is unable to provide exercises that simulate ambulatory activity.
U.S. Pat. No. 4,635,931 describes a device for exercising the leg and arm muscles of a person lying in bed. The device consists of the bellows that is fastened to the foot board of the bed whereby the bedridden patients can push and pull on the bellows. This is a resistance exercise device. Without energy storage or actuation, this device is not able to provide concentric and eccentric exercise. There is also no provision for the safe accommodation of body-weight-level forces by the bed structure.
U.S. Pat. No. 4,615,335 describes an apparatus for permitting the exercise of a bedridden patient while in bed. This device uses a motorized bicycle for the upper or lower extremity. The method of attachment to the bed is by fastening to the rail along the side of the bed. Because of the way this device is positioned on the bed a patient is not able to exercise both the left and right side at the same time; therefore it does not simulate functional activity.
No product exists that is capable of providing said adequate in-bed exercise for the thigh and leg muscles of bedridden patients. The present invention, an In-Bed Exerciser for use by persons in bed, addresses the shortcomings of the prior art. It can safely provide adequate exercise for the thigh and leg muscles in accordance with the said seven basic principles of resistance training. It can also prevent muscle atrophy during periods of bedrest and thus can be an important rehabilitation tool for any patient attempting to regain functional mobility.